With rapid development of electronic technologies, transistors are more widely used.
Some transistors have a parasitic diode. When an extremely high voltage is loaded at two ends of the transistor, the diode is usually first overshot by a reverse voltage, and then an extremely high current flows through a branch circuit in which the diode is located, and does not flow through a branch circuit in which the transistor is located, so that the transistor can be prevented from being overshot by a high voltage.
In a process of implementing this disclosure, the inventor finds that at least the following problems exist:
A parasitic diode of a transistor generally has a relatively poor reverse recovery feature. Reverse recovery means that a conducted diode accumulates a specific amount of electric charges, and when the diode is cut off, the diode releases the accumulated electric charges to form a current in a specific time until the electric charges are released. The relatively poor reverse recovery feature means that an electric charge release time is relatively long. In a transistor switching circuit, when a transistor enters a cut-off state from a conducted state, a parasitic diode needs a relatively long time to release a stored electric charge, a forward current on the parasitic diode cannot quickly disappear, and a relatively long time is required before a state in which a current is cut off can be entered. Therefore, a switching speed of the transistor is relatively low.